Most manufacturing industries use chromatography and other types of separation and detection systems to evaluate the process reactions or manufacturing process lines. For example, pharmaceutical manufacturers often use a chromatography system to monitor their process line by taking samples at various times or at different points along the process line to ensure that a manufacturing batch is to specification. Samples may include complex mixtures of proteins, protein precursors, protein fragments, reaction products, and other compounds, to list but a few. Other manufacturers may use their chromatography systems to profile a certain biochemical reaction, taking samples from the same point in the process line over time as the reaction progresses.
For every industry, preservation and transport of sample presents a particular challenge as it is imperative that sample represents the batch or flow stream that is being tested or otherwise investigated. During transport, changes in and to the physical and chemical makeup of the collected sample must be avoided for the measurements to be reliable. For example, the degradation of the sample due to environmental stress (i.e., heat, cold, oxygen) can cause an erroneous result. Furthermore, any sample preparation prior to the measurement should be performed with a minimum loss of sample and without unwanted modifications and avoiding the additional of extraneous impurties.
The manner of acquiring samples for analysis can be manually intensive. Typically, an individual draws sample from a process line, reactor, reactor stream or the like. He or she then carries it to the separation and detection system and loads it into the system for injection and analysis. Throughout this handling, care must be taken to label the sample properly and to ensure a well-documented chain of custody, or otherwise risk introducing uncertainty into the results.
If a sample needs to be converted to a form suitable for the measurement step, sample preparations such as filtration, quenching, dilution, or derivatization are made before sample injection into a liquid chromatography system. In this case, the sample preparation apparatus must be thoroughly washed to avoid contamination with the previous sample. Manual sample preparations can be wasteful and cost ineffective as larger amounts of the sample need to be taken. Manual sample preparation introduces the risk of irreproducible results and affords sources of error to be generated during sample analysis.
For example, manual sample preparation for chemical derivatization prior to the injection is very time consuming. After manually acquiring the sample, the individual must next thoroughly mix the sample with a reagent, or multiple reagents. Then, the individual must apply for example heat to the container within which the derivatization occurs, ensuring that the heat is applied evenly throughout the container for a specified time, sometimes hours, in order for the chemical reaction to go to completion. Each pre-analysis step can influence the overall accuracy and reliability of the results. In some cases, variations in the pre-analysis steps can introduce errors in the results that are greater in magnitude than the properties of the sample that are being measured.